Extracted the configuration of the container

Hey there,

I've extracted the configuration of the container so that it could be also used with an existing container instance.

I often have the need to have the container registered before I could pass it to Nancy. At the moment I have to do the configuration of Castle by myself, which means that I have to take care of possible changes in Nancy. As the Windsor bootstraper already has the knowledge it should provide its knowledge for configuration of an existing container.

Thoughts?